Blow-out preventer



June 7, 1932.

Original Filed Feb. 16. 1927 55 aw J7,

W. A. TROUT BLOW-OUT PREVENTER 5 Sheets-Sheet 1 Ma /role Mum/Y A w WTTORNEK June 7, 1932. w, TROUT 1,861,726

BLOW- OUT PREVENTER Original Filed Feb. 16. 1927 5 Sheets-Sheet 2 33 J/I/IZENTOZQ Patented June 7, 1932 UNITED. STATES PATENT: OFFICE WILLIAM A. TROUT, OF LOS ANGELES, CALIFORNIA, ASSIGNOB F ONE-HALF TO CHESTER A. RASHUSSEN, 0] LONG BEACH, CALIFORNIA snow-our rnnvmt'rnn.

Application filed February 16, 1927, Serial No. 168,547. Renewed November 18, 1931.

This invention relates to the oil producing industry and it relates particularly to a novel casing head.

When a well is partly drilled it is common 3 practice tolower a well easing into it and cement the well casing in place. When drill ing is recommenced a small size hole is drilled because a smaller drill which will pass through the well casing must be used. An-

other string of casing is later lowered into the well, the upper end thereof extending through the well casing. A casing head is used at the upper end of the well casing for providing a seal between the well casing and 16 the inner casing extended therethrough, for the purpose of preventing the gas of the well from escaping and for preventing the oil from-starting to flow.

Often in removing the drill pipe from the well for the purpose of renewing drill hits,

the excessive pressure from the underlying strata causes a blowout which usually demolishes the drilling equipment and often results in fatalities to workmen.

It is an object of my invention to provide a casing head which prevents blowouts.

It is another object of my invention to pro- 7 vide a casing head in which the packing member is fluid-operated.

Another object of the invention is to provide a casing head in which the packing member may be operated by the fluid-pressure of the well or by a fluid-pressure of an external source.

If the oil in the oil-bearing sands is hot when it starts to flow, the inner casing will be heated and will expand.

It is an object of this invention to provide around the upper end of the inner casing but automatically become active on the packing member if the well pressure exceeds the pres-.

sure of the external pressure source. Another object of the invention is to provide a casing head having a packing member a casing head which will form a tight seal.

which may centralize itself around the inner casing.

Other objects and advantages of the invention will be made evident hereinafter.

Referring to'the drawings in which I illustrate different forms of the invention:

Fig. 1 is a diagrammatic view showing the utility of the invention.

Fig. 2 is an enlarged vertical section of my invention.

Fig. 3 is a section taken on the line 33 of Fig. 2.

Fig. 4 is a section taken on the line 4.--4 of Fig. 2.

Fig. 5 is a section taken on the line 55 of Fig. 2.

Fig. 6 is a fragmentary section showing a packing gland applied to the upper end of the casing head.

Fig. 7 is a fragmentary view illustrating an alternative form of the invention.

Fig. 8 is a section taken on the line 8-8 of Flg. 7.

Fig. 9 is a protracted perspective view showing a packer of the second form of the 70 invention.

Referring particularly to Fig. 1, 11 is a well having an outer well casing 12 and an inner casing 13 whichmay be a well casing or a drill pipe. The inner casing 13 may be a casing which is permanently secured in the well 11 or may be a circulating tube or other pipe which is removable. Attached to the upper end of the well casing 12 is a gate valve 15 which may be closed after the inner 85 casing 13, if it is removable, is removed from the well. A b -pass pipe 16 having a valve 17 is connecte around the gate valve 15 for the purpose of equalizin the pressure in the well casing 12 on opposite sides of the gate valve 15 when the gate valve is closed so that it may be easily opened. A casing head indicated by the numeral 19, is attached to the well casing 12 above the gate valve 15. The details of the casing head 19 are illustrated in Figs. 2 to 6 inclusive.

Referring to these figures, the casing head 19 has a lower section 21, an intermediate section 22, an upper section 23, and a slip-seat or splder 24. These parts just enumerated cooperate to provide the body of the casing head. Each of the sections 21 to 23 inclusive, and the spider 24, are provided with flanges 26, and the flanges of adjacent sections are secured together by bolts 27. The inner casing 13 extends entirely through the body of the casing head 19.

be of less diameter than the opposite ends.,

The packing member is made of a pliable material such as rubber so that it may readily expand and contract according to the pressure applied thereagainst. The upper end .of the packing member 32 is provided with a conical face 33 which engages a complementary face 34 of the lower section 21. The packing member is attached to the annular flange 31 by bolts 35 which also clamp a ring 36 against the lower end thereof as illustrated in Fig. 2 attached to the lower end of the packing member 32 is a ring 37, this ring 37 being attached by bolts 38. Extending between the rings 36 and 37 are spacer bars 39 which are provided for the purpose of keeping the upper and lower ends of the packing member 32 spaced a proper distance. The packing member 32 is adapted to engage the 35 inner casing 13 and when there is a pressure in the well casing 12, this packing member 32 will form a seal around the inner casing 13. The packing member 32 provides a pressure chamber 40 in the outer part of the cavity 30, which pressure chamber 40 is connected to the upper end of the well casing 12 so that whenever there is a pressure in the upper end of the well casing 12 there will be a pressure against the packing member 32 which will force it into sealing contact with the inner casing 13.

The intermediate section 22 provides a cavity 45. Resting in the cavity 45, which is provided between the annular flange 31 and an annular flange 46, is an intermediate packing member 47. The packing member 47 is of the same character as the lower packing member 32, being made of a pliable material and being constricted at the central part so as to engage the inner casing 13. The upper end of the packing member 47 engages the annular flange 46 and the lower end thereof engages the annular flange 31. The ends are retained in engagement with the ancavity 45 and it may therefore move laterally in any direction so that it may centralize itself around the inner casing 13. The packing member 47 forms an outer annular part of the cavity 45 into a pressure chamber 51.

The upper section 23 provides a cavity '55 in which an upper packing member 56 is located. The upper packing member 56 is of a design similar to that of the packing members 47 and 32, being annular and constricted at the center, and being formed of a pliable material. The upper and lower ends of the packing member 56 have shoulders 57 ,which are clamped in annular channels 58.

The packing member 56 forms an annular pressure chamber 59 in the outer part of the ca y 5- Extending adjacent to the body of the casing head 19 is a fluid-pressure pipe 60 having branch pipes 61 which are connected to the pressure chambers 59 and 51. The branch pipes 61 are provided with valves 62. One end of the fluid-pressure pipe 60 is connected to an external fluid-pressure source, and the other end thereof is connected to the upper part of thewell casing 12. A check valve 64 is placed in thefluid-pressure pipe 60 adjacent to where it-connects to the well casing 12 to prevent a flow of fluid through the fluid-pressure pipe into the well casing. A check valve 65 is placed in the fluid-pressure pipe 60 between the upper branch pipe 61 and the external fluid-pressure source to prevent,a reverse flow in that portion of the fluid-pressure pipe 60. A bleeder pipe 67 having a valve 68 is connected to the fluid pressure pipe 60 between the check valves 64 and 65. A valve 69, normally closed, connects the fluid-pressure pipe 60 to the atmosphere.

When the valves 62 in the branch pipes 61 are open and there is a fluid-pressure in the well casing 12, the check valve 64 will be opened and the check valve 65 will be closed. The fluid from the upper end of the well casing 12 will flow through the fluid-pressure pipe 60, the branch pipes 61 and into the pressure chambers 51 and 59. The packing members 47 and 56 being pliable, will be forced into sealing contact with the inner casing 13. The lower packing member 32 being in direct communication with the upper end of the well casing 12, will also be forced into sealing contact with the inner casing 13. The external fluid-pressure source is maintained at a certain pressure, and when the pressure in the well drops below this pressure the check valve 64 will close and the check valve 65 will open, so that the pressure in the pressure chambers 51 and 59 will be maintained by fluid supplied by the external fluid-pressure source. When it is desired to release the pressure in the pressure chambers 51 and 59, a valve 70 in the fluidpressure line 60 above the cheek valve'65 is V of the inner casing 13 so that they may move thereby.

The spider 24 has. a conical'seat 75 which is adapted to receive pipe-supporting slips 76 which are adapted to support the upper end of the inner casing 13 when it is standing in the well 11 and when it is being removed from the well. The slips 76 prevent a downward movement of the upper end of the inner casing 13 but permit an upward movement thereof. If the inner casing is expanded, the upper end may move upward. It should be noted that the packing members 32, 47 and 56 are all so designed that they provide a tight seal around the inner casing 13 but permit the upper end to move vertically without breaking the seal. The slips 76 are not used if the inner casing 13 is a rotating drill pipe, as would be the case in using my invention in drilling operations.

In Fig. 6 I show a packing gland placed in the spider 24. This packing gland may be used when the inner' casing 13 is secured in the well and it is desired to form a tight seal around the inner casing 13 at the upper end of the casing head 19. The packing gland consists of a packer 78 which is placed in the-seat 75 and compressed by means of a follower 79 attached to the upper flange 26 of the spider 24 by bolts 80.

A complete operation of this form of the invention is as follows.

After the casing or drillpipe has been placed in the well, the packing head of the invention may be installed as illustrated in Fig. 2. If there is a fluid-pressure in the well, this fluid-pressure will act on the packing members, as previously explained, and force them into fluid-tight contact with the inner casing 13. Until a fluid-pressure is applied to the packing members the casing 13 is free to revolve or move upward or downward any distance, there being no seal at the upper end thereof. Immediately upon a fluid-pressure occurring in the well all three packing members will be automatically forced into fluid-tight engagement with the inner casing 13; If the fluid-pressure in the well drops'below a certain point it is obvious that a tight seal wouldnot be provided and that there would be a loss of fluid. It is desirable to prevent a loss of fluid since it might cause the oil to blow in before the surface equipment was prepared for it: also because a considerable loss of gas will reduce the natural flowing capacity of the well. In order to meet this occasion the external fluid-pressure source is provided and comes into operation when the fluid-pressure in the well drops below a pressure sufiicient to maintain a tight seal.

If it is desired to raise the inner casing 13 throughthe outer casing 12, and maintainthe seal therebetween, it is possible to draw the inner casing upward, and allow the cou- I plings 71 to pass successively through the sealing members. The sealing members not in engagement with the coupling maintain a positive seal. with. the inner casing so that no gas or other fluid can escape.

. When the pressure in the well has decreased and it is desirable to remove the pressure from the packing members so that the inner casing or drill pipe 13 may be removed, the valve 69 in the fluid-pressure pipe 60 is opened, this relieving the pressure inv the fluid-pressure pipe 60 between the check-valves 65 and 68 and the pressure in the pressure chambers 51 and 59, the valve 70 being closed at this time. The inner casing or drill pipe 13 may be removed when the pressure on the packing members has been relieved. When the inner casing or drill pipe 13 is entirely removed from the well 11, the gate valve 15, shown in Fig. 1. may be closed and the apparatus to accommodate a flow of oil from the well may then be attached. When the gate valve 15 is to be again opened, the-valve 17 in the by-pass 16 is opened for egualizing the pressure on the opposite sides 0 the gate valve so that it may be easily moved into open position. p

The intermediate packing member 47 is so designed, as previously explained, that it may centralize itself around the inner casing 13 and thus effectively provide a tight seal. The frame 48 is provided for maintaining the opposite ends of the packing member 47 in engagement with the annular Walls 31 and 46 so that a pressure may be maintained in that portion of the cavity 45 which forms the pressure chamber 51. The lower packing member 32 is prevented from collapsing by the spacers 39 which are extended between the upper and lower rings 36 and 37.

It is often desirable to have the fluid-pressure pipe 60 in communication with a slush pump which supplies a mud to this pipe under pressure, this mud filling the pressure chambers 51 and 59. If an excessive amount .of gas pressure builds up, so that a flow of together by bolts 93. Supported by the upper section 91 is a cover 94. The .inner casing or drill ipe 13 extends through these parts of this orm of the invention, which partsthe shoulder 116 so that-a tight seal may be provide the body. The upper section 91 provides a cavity 95 in which a packin member 96 is placed. This packing mem r 96 is made of a pliable material and is annular in sha e, being of smaller diameter at the cen- 19 tra part thereof so as to be capable of conveniently en aging the inner casing 13 The upper endo? the packin member 96 is provided with a flange 97 w ich is attached to a wall 98 of the cover 94 by means of bolts 99.

A conical face 100 of the flang? 97 engages a complementar face 101- of t e upper section 91. A per orated frame 103 surrounds the packing member 96 and is attachedto the upper flange ,97 thereof by means of the bolts 99. A cylindrical part 104 of the frame 103 has a flange 105 provided at the lower end thereof which engages a lower flange 107 of the packing member 96. This flange 105 is attached to the flange 107 of the packing member 96 by bolts 109 which also attach a lower flat ring 110 to the lower face of the flange 107. The ring 110 is adapted to engage an annular wall 112 formed at the lower end of the cavity 95 and provided by the upper part of the lower section 90. Extended downward from the outer part of the annular flange 105 of the frame 103 is an annular lip 113 which supports the outer edge of the lower flange 107 of the packing member 96 and clamps on the rin 110 in engagement with the upper face 0 the annular wall 112. The frame 103 retains the packing member 96 in the position shown in the drawings, and maintains the lower flange 107 thereof in fluid-tight engagement with the upper face of the annular wall 112 by means of the ring 110. 1 The wall 98 of the cover 94 rests in annular recesses 115 formed at the upper end of the upper section 91 in engagement with an annular seat 116.. Forthe purpose of retaining the wall 91 in place, I provide a lockin ring 117. The locking ring 117 has a cylin drical portion 118 which surrounds the upper portion of the upper section 91. Extended inward from the lower part of the cylindrical portion 118 is a wall 119 which engages a face 120 of. the upper section 91. Extended inward from the upper part of the cylindrical portion 118 are lugs 121 which are separated by spaces 122. The periphery of the wall 98 of the cover 94 is rovided with lugs 123 which are separate by spaces 124. When the locking ring 117 is in the position shown 90 in the drawings, the lugs 121 are above the lugs 123 and the cover 94 is retained in place. When it is desired to remove the cover, the lugs 121 are moved into positions above the spaces 124 so that the lugs 123 of the wall 98 may move through the spaces 122 of the locking ring 117. The lockin rin may be turned by manually engageable an e 126. Clamp screws 127 are provided in the locking ring 117 for clamping the wall 98 tightly against formed.

The cover 94 has a cylindrical projection 130 providing a packing cavity 131. Adapted to be placed in the packin cavity 131 is a packer 132 which consists o a lower metallic ring 133, a central packing member 134 and an upper metallic. ring 135. The lower rin 133 is hinged at 137 sothat it may be easily p aoed around the inner casing 13 and it is provided with a lower conical face 138. adapted to engage a lower conical seat-139 formed at the lower end of the cavity 131. The packer 134 is split, as indicated at 141, so that it may be placed around the inner casing 13. The uppermetallic ring 135 is hinged at 143 and has an upper annular shoulder 144. Engaging the upper annular shoulder 144 areinserts' 146 which are forced downward by a nut 147 screwed onto the cylindrical projection 130. When the nut 147 is screwed downward the upper metallic ring 135 is forced downward so that the'packingmember 134 is compressed into fluid-tight engagement with the wall of the cavity 130 and with the inner casing 13. Thecasing 13 is prevented from moving upward by engagement of a collar 149 thereof with a lower face of the lower metallic ring 133.

A fluid-pressure pipe 155 is connected to the lower section so as to be in communication with the upper end of the well casin 12, this fluid-pressure pipe 155 having a chec valve 156. A branch pipe 157 is connected to the outer part of the cavity which provides a pressure chamber 160 and is connected to the fluid-pressure pipe 155, this branch pipe 157 having a valve 161. Above the branch pipe 157 in the fluid-pressure pipe 155 is a check valve 163. The annular wall 112 is provided with a plurality of openings 164 which connect the upper end of the well casing 12 to the ressure chamber 160. The upper ends of the openings 164 are closed by a valve ring 165 which seal these openings when the ring is in the position shown in the drawings, occupying this position when the pressure in the pressure chamber 160 is greater than the pressure in the well.

When there is a fluid-pressure in the well the valve ring 165 is unseated and the fluid passes into the pressure chamber 160, forcing the packing member 96 into fluid-tight engagement with the inner casing 13. The fluid-pressure pipe 155 is connected to an external fluid-pressure source, not shown, where a certain pressure is maintained at all times. If the fluids-pressure in the well drops below the pressure i c- 1: :met-nal fluidpressure source the check valve 163, which is closed when the well pressure i 5 high opens and the valve rin 165 seats so as to close the openings 164. it this time the packing member 96 is maintained in fluid-tight engagement by fluid-pressure supplied by the external fluid-pressure source. When it is desired to release the pressure in the pressure chamber 160, a valve 170 in the fluid-pressure pipe 155 may be opened.

I claim as my invention: 1. A casing head comprising: a body adapted to be supported at the upper end of an outer casing, said body providing a cavity; an annular packing member dis osed in said cavity, said packing member orming part of said cavity into a pressure chamber, said packing member being arranged to surround an inner casing; a fluid-pressure pipe connected to said outer casing and an external pressure source; a branch pipe connected to said pressure chamber and said fluid-pressure pipe; a check valve between said fluidpressure pipe and said outer casing; and a check valve between said fluid-pressure pipe and said external pressure source.

2. A casing head comprising: a body adapted to be supported at the upper end of an outer casing, said body providing a cavity; an annular packing member disposed in said cavity, said packing member forming part of said cavity into a pressure chamber, said packing member being arranged to surround an inner casing; a fluid-pressure pipe connected to said outer casing and anexternal pressure source; a branch pipe connected to said pressure chamber and said fluid-pressure pipe; a check valve between said fluidpressure pipe and said outer casing; a check valve between said fluid-pressure pipe and said external pressure source; a bleeder pipe,

connected to said casing and to said fluidpressure pipe; and a valve in saidbleeder P P well in which subterranean pressure exists, for maintaining a seal between an outer casing and an inner c'a'sing having couplings of larger diameter than the inner casing sections and for permitting the removal or installation of the inner casing without losing control of the well, said blowout preventer comprising: a body adapted to be connected to said outer casing, said body providing a passage through which said inner casing extends, said passage being large enough to allow said couplings of said inner casing to pass therethrough; and sealing means including a resilient annular packer member extending into said passage andforming a seal around said inner casing, said annular packer member having both the u per and lower ends thereof sealed against slib wardly between the inner and outer casing, said annular packer member commumcatlng with a source of pressure whereby to cause the as inner surface thereof to be resiliently and 3. A blowout preventer for use on an oil terranean pressure passing up-- '1 automatically engaged with the inner casing. 4. A blowout'preventer for use on an oil well in which subterranean pressure exists for maintaining a seal between an outer, casing and an inner casing having couplings of extending into said passage and forming a seal around said inner casing, said annular packer members having both the upper and lower ends thereof sealed against subterranean' pressure'arising upwardly between said inner and outer casings, said packers having a source of pressure communicating to cause the inner surface thereof to be resiliently and automaticallyengaged with the mner casing. a ,7

5. A blowout preventer for useon anoil well in which subterranean. pressure exists, for maintaining a seal between an outer casing and an inner casing having-couplings of larger diameter than the inner casing sections and for permitting the removal or installation of "the inner casing without losing control of the well, said blowout preventer comprising: a body adapted to be connected to said sage being large enough to allow said couplings of said inner casing to pass there through; and sealing means including a pinrality of resilient annular packer mem rs extending into said casin and forming a seal around said inner casing, said annular packer members having both the upper and lower ends thereof sealed against the subterranean gases passing upwardly between the inner and outer casings; said packers having pockets and means for laterally injecting fluid pressure through said body member into the pocket portions of the packers whereby to urge the same resiliently into engagement with the inner casing.

6. A blowout preventer for use on an oil well in which subterranean pressure exists, for maintaining a seal between an outer casing and an inner casing having couplings of larger diameter than the inner casing sections and for permitting the removal or installation of the inner casing without losing control of the well, said blowout preventer comprising: a body adapted to be connected to said outer casing, said body providing a passage through which said inner casing exso I rality of resilient annular pocket members ass therethrough; and sealing means includmg a resilient annular packer member, a recess provided by said bod member for receiving said packer mem er, said packer member being disconnectedly situated within said recess whereby it may float therein, and means for introducing fluid pressure to the rear of said packer whereby to maintain the same resiliently in engagement with the inner casing. I

7. A blowout preventer of the character described, a bod adapted for connection with the upper en of a well casing and having an o ening therein through which a sectional mem ber connected by con lings is freely passable; a recess'provided y said body, a sealing member disconnectedly situated within said recess, fluid pressure means for urging the sealing member into engagement with said sectional member to seal said opening, said recess permitting the sealing member to be bodily movable therein when the sealing member is engaged by couplings of the sectional member.

8. A blowout preventer of the character described: a body adapted for connection with the upper end of a well casing and having an opening therein through which a sectional member connected by couplings is freely passable; a recess provided by said body, a sealing member disconnected and floatingly arranged within said recess, fluid pressure means for urging the sealing member into engagement with the sectional member to seal said opening, said recess permitting the sealing member to be shifted backwardly thereinto when the sealing member is engaged by the couplings of the sectional member.

, 9. A blowout preventer of the character described: a body adapted for connection with the upper end of the well casing and having an opening therein through which a sectional member connected bya coupling is freely passable, a recess provided by said body, a sealing member dlsconnectedly situated within said recess and having its ends in tight engagement with the walls of the recess to prevent the entrance of gases arising between. the well casing and sectional member into the sealing member, said sealin member having a pocket in the rear thereo and fluid pressure means communicating with the pocket of the sealing member for urging the same into engagement with the sectional member to seal said opening.

10. A blowout preventer of the character described: a body adapted for connection with the inner end of the well casing and having an opening therein through which a sectional member connected by couplings is freely passable, said body member having a plurality of inwardly extending flanges delinmg a recess, a sealing member disconnectedly situated within said recess and having its ends engaging said flanges to seal the same, means for introducing fluid pressure laterally with respect to said body member for urging the sealing member into engagement with the sectional member to seal said opening, said sealing member being adapted to float within said recesses when engaged by said couplings of the sectional member.

11. A blowout reventer for use on an oil well in which subterranean pressure exists,

for maintaining a seal between an outer cas-.

ing and an inner casing having couplings of larger diameter than the inner casing sections and 'for permitting the removal or installation of the inner casing without losing control of the well, said blowout preventer comprising: a body adapted to be connected to said outer casing, said body providing a passage through which said Inner casing extends, said passage being large enough to allow said couplings of said inner casing to pass therethrough; and sealing means including a resilient annular packer extendin into said passage and forming a seal aroun said inner casing, said resilient packer permitting said inner casing to be moved therethrough, and said resilient packer being engaged and enlarged by one of said couplings, said resilient packer engaging said coupling during its passage through said resilient packer, and when said coupling has been passed through said resilient packer, said resilient packer automatically engaging said inner casing, said packer being substantially concavo-convex in formation and being disconnected with CERTIFICATE OF CORRECTION.

Patent No. 1,861,726. June 7,1932.

WILLIAM A. TROUT.

It is hereby certified that error appears in the printed specification of the above numbered patent requiring correction as follows: Page 5, line 81, claim 4, for "pocket" read packer; and that the said Letters Patent should be read with this correction therein that the same may conform to the record of thecase in the Patent Office.

Signed and sealed this 4th day of October, A. D. 1932.

M. J. Moore, (Seal) Acting Commissioner of Patents. 

